Electric igniting device.



PATENTEDIHMAR. 10,1903.

2 SEEETS-BHEBT 1.

F. STURM.

ELECTRIC IGNITING DEVICE.

APPLICATION FILED JAN. 20.1901.

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PATENTBD MAR. 10, 1903.

P. STURM. ELECTRIC IGNITING DEVICE.

APPLIGATION FILED JAN. 26, 1901.

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FRIEDRICH STURM, OF STUTTGART, GERMANY.

ELECTRIC IGNITING DEVICE.

SPECIFICATION forming part of Letters Patent N 0. 722,333, dated March10, 1903.

Application filed-Ianuary 26, 1901. Serial No. 44,894, (No model.)

To all whom it may concern:

Be it known that I, FRIEDRICH STURM, a citizen of the German Empire,residing at Stuttgart, in the Kingdom of lViirtemberg, Germany, haveinvented certain new and useful Improvements in Generators for IgnitionDevices; and I do hereby declare the following to be afull, clear, andexact description of the invention, such as will enable others skilledin the art to which it appertains to make and use same.

The electric devices for igniting the explosive mixtures of gas engines,motor cars, and the like as hitherto employed all exhibit the drawbackthat the period of ignition of the explosive mixture in the cylindercannot be altered at any time as regards the position of the movingcylinder-piston. The socalled front or back ignition cannot be regulatedin a suitable manner, and thereby the number of revolutions and actionof the motor cannot be altered. In the magnetoelectric igniting devicesat present most frequently employed and which have reciprocatingarmatures, the possibility of forming a spark, as is well known, is onlypresented at the moment when the surfaces of the armature-arms move awayfrom the edges of the pole-pieces. At this moment in order to produce aspark, and thereby effect the ignition, the igniting-lever situated inthe explosionchamber of the motor must also simultaneously separateitself from the igniting-pins. The movement of the armature and that ofthe igniting-lever must thus exactly correspond in order to produce asure working of the former. As the ignition of the explosive mixture inthe cylinder must take place only at a given position of the piston, themovement of the piston must also coincide with that of the ignitingdevice and of the igniting-lever. Now, as every expert knows, theproduction of a coincidence in movement of the piston, armature, andigniting-lever precisely is not always a simple matter and requiresexact transmission-gear for operating the armature and also an exactadjustment of the lever for operating the igniting-lever. The ignitionof the explosive mixture, moreover, always takes place in adefinitely-determined position of the piston.

The present invention has for its object to provide a separatearrangement in the igniting device for altering the moment ofignition-that is to say, to allow of the ignition taking place in anysuitable position of the piston. By this means the previously-mentionedcoincidence in the movements of the armature, igniting-lever, and pistonis more easily brought about, and, further, the action of the motor evenwhile running may be suitably adjusted or altered, which is of thehighest importance, more particularly for motor-cars. This peculiararrangement consists in mounting the pole-pieces adj ustablythat is tosay, revolubly instead of firmly, as previously-in such a way that thepoint of separation of the edges of the armature and pole-pieces may beshifted and the moment of ignition be thus altered.

In the accompanying drawings, Figures 1 and 2 are longitudinal and crosssections, Fig. 3 a plan view, and Fig. at a side view, of a generatorprovided with adjustable polepiecesfor instance, with three magnets.Figs. 5 and 7 are respectively an elevation and cross-section of theadjustable polepieces connected with one another; and Fig. 6 is alongitudinal view, partly in section, of the armature here employed,which is, for instance, assumed to be constantly rotating. Fig. Sis adiagrammatic view illustrating one apparatus which may be employed forthe adjustment of the device for moving the igniting-lever.

Fixed poles 15 are screwed on magnets 6. Their inner part is turned outsemicircularly to receive adjustable pole-pieces 9, which are revolublymounted. Within the latter there lies an armature 1, plates 2 beingscrewed on the ends of its arms to carry pins 3 and 4, which form theaxis of rotation for the armature. These pins are mounted in bearings 5,screwed on the bed-plate 7 of the device and on the fixed poles 15.

The generator is driven in the ordinary manner by means of a cog-Wheel,chain-wheel, lever, or the like, (notshown in the drawings,) mounted onone of the pins 3.

The two adjustable pole-pieces 9 are connected with one another at bothends by means of disks 24:, which lie in recesses in the bearings 5 andfor which thepins 3 and 4 of the armature serve as guides. Aloosely-revoluble disk 10, mounted on the hub of one bearing 5, servesfor adjusting the pole-pieces 9, which disk is coupled, by means of aneye 11, with a rod 12 and may be revolved to a suitable extent by meansof this latter. The disk 10 is firmly connected with the polepieces 9 bymeans of screws 14, which pass through segmental slots 13, formed in thebearing 5, so that by turning the disk the pole-pieces are also turnedwith it. By a suitable adjustment of the disk 10 the moment of ignitionmay thus be suitably altered. Of course the adjustment of thepole-pieces must be accompanied by a suitable adjustment of the devicefor moving the igniting-lever, which may be effected most simply byadjusting in a similar manner the cam or the like which operates theigniting-lever when the pole-pieces are adjusted by means of the disk10, such adjustment taking place from this latter. Such a means is shownin Fig. 8. In this construction the ignition-arm to must separate fromthe ignition-stud 'Lt at that moment when the edges or margins of therotary armature leaves the edges of the adj ustable pole-pieces. Thismay be done by providing the disk 10 (which is connected to theadjusting-lever 2 by a coupling-rod 12, pivoted to extension 11 of saiddisk 10) with an extension 11, to which is connected the end q of therod 19, said end q having a slot 0,

through which passes a screw 1*, threaded into the extension 11. The end(1 of the rod p is acted upon by the continually-rotating cam m, mountedon the armatureshaft, and transmits its reciprocating motion through therod '15 to a rock-arm i), which oscillates the lever or electrode 10into and out of contact with the stud u, the rod 15 being acted on by aspring 8 to return it to its normal position. The armatnre-circuitisthrough the wire 0 to the stud u and through the rods 19 and t to thelever to. This structure is all old and well known and forms no part ofmy invention, except the arrangement of the same in combination with theadjustable disk 10, and the adjustable pole-pieces of the generator andits method of operation will be obvious to those skilled in the art inview of the description hereinbefore given.

In order that the same igniting device may be utilized for motors havingvery large and very small numbers of revolutions, a great conductiveresistance is necessary in the armature, for which object very thinwires of only approximately thirty millimeters in thickness are employedand which are insulated from one another in layers on the armatu re,although such wires are already well insulated themselves. One end ofthe armature-wire is insulated from the device by a vulcanite socket 17being inserted in the hollow pin 4 of the armature, in which socket aconducting-pin 16 is inserted, on which the end of the wire is held fastby means of a screw 18. The other end of the armaturewire is connectedto the armature-core in a well-known manner. The pin 16 encounters a pin21, which is elastically and flexibly mounted in a metal yoke 19 and isalso screwed firmly to a set-screw 22. One Wire 0 leads from the pin 21to the igniting-pins, so that by means of this wire the coil 8 of thearmature 1 is connected with the igniting-pins, while the igniting-leveris conductingly connected with the igniting device by means of themechanism which operates it. When the igniting-pins and igniting-leverencounter one another,contact is established. The metal yoke 19 isinsulated from the igniting device by means of non-conductingintermediate layers 20 of hard rubber or the like.

If the disk 10 and pole-pieces 9 be adjusted by means of thecoupling-rod 12, operated from a suitable place, the moment of ignitionwill be altered with regard to the actual position of the piston, sothat the ignition is adjusted for a suitable position of the piston, andfront or back ignition may be employed, as required. The number ofrevolutions of the machine and their effectiveness is therebyinfluenced, which is of great advantage, more particularly formotor-cars.

The adjustable pole-pieces can of course be employed equally well inigniting devices with reciprocating armatures as in those withconstantly-rotating armatures.

By the use for the armature of a wire coil which offers a greaterresistance the same igniting device can be employed for machines makingany number of revolutions per minutesay from twenty up to threethousandwhile for motors with a greater number ofrevolutionsforinstance, over eight hundred per minuteaconstantly-rotating armature may be employed in place of a reciprocatingarmature.

The igniting devices hitherto employed with reciprocating armatures hadalso, as is well known, the drawback of not working correctly when thenumber of revolutions exceeded eight hundred per minute so far asregards a sure igniting, as at each double oscillation two dead-pointsof the armature have to be overcome, so that the number of revolutionscapable of being executed by motors provided with such igniting devicesis limited. The igniting devices with constantly-rotating armatures may,on the other hand, as already pointed out, be employed with aconstantlylutions.

Having now particularly described and asp certain ignition for thelargest number of revo- 2. The combinati0n,with an igniting-lever, andadjustable means for operating the same, of a generator arranged tosupply electricity through the igniting-lever, and provided with anadjustable pole-piece.

3. The c01nbination,with an igniting-lever, and an adjustable cam foroperating said lever, of a generator arranged to supply electric currentthrough the igniting-lever, and provided with adjustable pole-pieces. no

In testimony whereof I have affixed my signature in presence of twowitnesses.

FRIEDRICH STURM. Witnesses:

A. DRAUTZ, WM. HAHN.

